It is known in the copper leaching art that pyrite (FeS2) may be used as a catalyst in the chemical leaching of copper from chalcopyrite concentrates in an acidic sulfate leach solution. Dixon et al., US 2005/0269208 A1, published Dec. 8, 2005, discloses a process for leaching copper from chalcopyrite concentrates using pyrite as a catalyst for ferric reduction in order to eliminate passivation of the chalcopyrite surface. The process is carried out under conditions whereby pyrite is not materially oxidized.
Pyrite from different sources may catalyze the rate of chalcopyrite leaching differently, some pyrites accelerating the rate more than others. It would be desirable to be able to accelerate the rate of leaching to a high degree irrespective of the source and properties of the pyrite used as a catalyst.